These statistics represent low-level information used by the MySQL optimizer to calculate which index to use when querying an InnoDB table.
This information is derived from in-memory data structures rather than corresponding to data stored on disk.

This INFORMATION_SCHEMA table presents a wide variety of InnoDB performance information,
complementing the specific focus areas of the PERFORMANCE_SCHEMA tables for InnoDB.
With simple queries, you can check the overall health of the system.
With more detailed queries, you can diagnose issues such as performance bottlenecks,
resource shortages, and application issues.

INNODB_BUFFER_PAGE_LRU table holds information about the pages in the InnoDB buffer pool,
in particular how they are ordered in the LRU list that determines which pages to evict from the buffer pool when it becomes full.

The INNODB_FT_DEFAULT_STOPWORD table holds a list of stopwords that are used by
default when creating a FULLTEXT index on an InnoDB table. For information about the
default InnoDB stopword list and how to define your own stopword lists.

stopword
In a FULLTEXT index, a word that is considered common or trivial enough that
it is omitted from the search index and ignored in search queries.
Different configuration settings control stopword processing for InnoDB and MyISAM tables.